﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo4
{
    class Square:Shape

    {
        protected double sideLen;
        public double Sidelen
        {
            get { return this.sideLen; }
            set { this.sideLen = value; }
        }
        public override void GetArea(double a)
        {
            // base.GetArea(a);
            double result = a * a;
            Console.WriteLine("正方形面积"+result);
        }
    }
}
